/*
For a positive integer n, let f(n) be the sum of the squares of the digits (in base 10) of n, e.g.
f(3) = 32 = 9,
f(25) = 22 + 52 = 4 + 25 = 29,
f(442) = 42 + 42 + 22 = 16 + 16 + 4 = 36
Find the last nine digits of the sum of all n, 0 &lt; n &lt; 1020, such that f(n) is a perfect square.

Anser:
Time:
*/
package main

import (
	"fmt"
	"time"
)

func main() {
	tstart := time.Now()



	tend := time.Now()
	fmt.Println(tend.Sub(tstart))
}